The present invention is related to MPEG (Moving Picture Experts Group) encoded transport streams containing multiple programs and, in particular, apparatus and method for selecting at least one program from the MPEG encoded transport stream, and for recording and reproducing the program without a need to determine the program contents of that stream.
Recently, in the U.S. and Europe, a system has been introduced for encoding video and audio signals, transmitting the encoded signals via a communications satellite and decoding the encoded signals at a receiving side for subsequent use by subscribers. A high efficiency encoding technique, such as the MPEG, for example, may be used in such a system, where a receiver is typically referred to as a set top box.
In accordance with this system, a transport stream carrying varying programs is received via an antenna; a converter converts the received transport stream to another frequency (a down-conversion operation); and a transport stream corresponding to a desired program (channel) is selected from the multiple channel transport streams. Next, video data and audio data from the selected program (channel) are separated from each other and subsequently decoded by a decoder. The decoded video and audio data are then transmitted to a conventional monitor or an analogue video tape recorder (VTR) for viewing or recording of the program, respectively.
It is known that digital recording/reproducing devices can record encoded bit stream data and then reproduce the encoded data for a subsequent decoding operation. Namely, the encoded bit stream data are not decoded prior to the recording/reproducing operations. It is desirable for these digital recording/reproducing devices to record/reproduce the encoded transport stream of the digital broadcast in order to prevent degradation of the picture quality during the recording/reproducing operations. In this case, the encoded picture reproduced by a digital recording/reproducing device maintains the same quality as when it is received by the set top box.
Since the transport stream is encoded, however, information about its program contents is not known, except that the length of a transmission packet is typically 130 bytes. If such a transport stream is recorded as it is (that is, without decoding) and then later reproduced, the transport stream can not be properly decoded by the decoder because it is unknown how many programs have been recorded by the digital recording/reproducing device.
A need therefore exists for a device that overcomes the above disadvantage.
It is therefore an object of the present invention to select, record and reproduce an encoded MPEG transport stream.
Another object of the present invention is to provide a system including an antenna, a converter, a set top box, a digital recording/reproducing device, and a monitor TV for selecting, recording and reproducing an encoded MPEG transport stream.
It is a further object of the invention to select an MPEG encoded transport stream from multiple MPEG encoded transport streams and to add additional data to the program contents of each of the packets in the selected MPEG encoded transport stream for correct reproduction and decoding.
According to one aspect, the invention includes a system for processing an MPEG encoded transport stream carrying packets with program contents. The system includes an antenna for receiving the MPEG encoded transport stream transmitted at a first frequency; a converter connected to the antenna for converting the MPEG encoded transport stream to a second frequency different from the first frequency; apparatus, such as a set top box, connected to the converter for processing the converted MPEG encoded transport stream such that each of the packets has additional data added to its program contents; a digital recording/reproducing device connected to the set top box for recording/reproducing the additional data with each of the packets; and a monitor TV connected to the set top box for displaying the program contents after the recorded additional data with each of the packets are reproduced by the digital recording/reproducing device and are decoded by the set top box.
In accordance with another aspect of the invention, the additional data includes (1) information for indicating how many programs are contained in the MPEG encoded transport stream; (2) information for indicating an error in the MPEG encoded transport stream; and (3) information for indicating a transition point representing a beginning of a program in the MPEG encoded transport stream.
In accordance with still another aspect of the invention, each of the packets conforms to an IEEE 1394 standard.
In accordance with yet another aspect of the invention, a method is provided for processing MPEG encoded transport streams, each carrying packets with program contents. The method includes the steps of selecting an MPEG encoded transport stream and attaching additional data to the program contents of each of the packets in the selected MPEG encoded transport stream.
The above and other objects, features and advantages of the present invention will become more apparent from the accompanying drawings, in which like reference numerals are used to identify the same or similar parts in several views.